1) Field of the Invention
The field of this invention relates to vehicle towing apparatuses and more particularly to a dolly-type of apparatus which is to be utilized to tow a tractor-type vehicle in conjunction with a towing vehicle.
2) Description of Related Art
Conventional earth-moving equipment is designed to be transported from one job location to another job location. Generally, this transportation is accomplished by the means of some form of a trailer or a truck with the trailer or truck being designed to be adaptable to the requirements of the road. Thus, local road laws and regulations play an important part in the design of earth moving equipment that is intended to be generally used "off the road".
A backhoe is a power digging machine consisting of a jointed arm with a bucket that scoops toward the operator as the bucket is operated. The bucket is mounted at the back of a tractor or other vehicle and due to its pulling motion, is like a hoe. Thus, the name backhoe. Normally, the entire vehicle is referred to as a backhoe. In the most common configuration, the entire vehicle constitutes a tractor with the digging bucket mounted at the rear end and a loading bucket mounted at the front. This is an exceedingly common form of earth-moving heavy equipment.
Backhoes come in various sizes. Most backhoes are not capable of traveling at any significant speed making it impractical for backhoes to be driven under their own power from location to location. Normally, the backhoe must be hauled requiring such to be moved by means of roadways. The most common way to haul a backhoe is either to chain it onto a large flatbed truck or to chain it onto a trailer behind a towing vehicle such as a truck.
There are certain disadvantages to these methods of hauling a backhoe. On a flatbed truck, the backhoe is very high creating a high center of gravity with the overall rig being quite heavy. A high center of gravity is obviously more prone to tipping than a low center of gravity. On a trailer, although the resulting center of gravity is lower, its overall length makes it hard to handle by the operator of the towing vehicle. The overall weight of such a rig is relatively heavy which makes the rig hard to handle because of the weight.
Aforementioned both types of rigs are heavy and cumbersome making road safety somewhat less than ideal. Recently there is being instituted in several States new restrictions on the licensing of drivers who wish to drive such rigs. Even a relatively small backhoe on a trailer behind a dual wheel pickup truck will be considered over the weight limit for a regular driver's license. Qualifying for the correct license will be difficult for many individuals which will result in a shortage of certified drivers for such rigs.